Saw chuck

ABSTRACT

A chuck for a portable reciprocating power saw wherein the chuck is of a minimum length and will firmly hold saw blades of various widths.

United States Patent 1 Anderson et al.

[ Aug. 28, 1973 SAW CHUCK Inventors: Charles L. Anderson; AndrewAnderson, both of Rt. 1, Box 198, Antioch, Ill. 60030 Filed: June 5,1972 Appl. No.: 259,799

US. Cl. 30/392, 83/698 Int. Cl B271) 11/06 Field of Search 30/166, 392,393, 30/394, 374, 375, 376, 377; 83/699, 697, 698; 279/83; 145/108 R,108 A, 108 13 References Cited UNITED STATES PATENTS 6/1907 Booth 279/832,619,132 11/1952 Pierce 30/394 3,056,437 10/1962 Mittins 30/3743,412,767 11/1968 Green 30/392 3,496,972 2/1970 Rees 30/376 PrimaryExaminer-James L. Jones, Jr Assistant Examiner-J. C. PetersAttorney-Edward L. Benno 1 1 ABSTRACT A chuck for a portablereciprocating power saw wherein the chuck is of a minimum length andwill firmly hold saw blades of various widths.

5 Claims, 5 Drawing Figures SAW CHUCK BACKGROUND OF THE INVENTION Manydifferent chucks have been and are presently used on portablereciprocating power saws. Reciprocating power saws are generally soldwith integral chucks by the manufacturer of the saw, and such chucks arecommonly constructed to only accept the particularly shaped saw bladessold by the manufacturer of the saw. Such arrangements are uneconomicaland inefficient because the user of the saw must constantly keep a stockof special blades on hand.

Further, many chucks presently used on portable reciprocating power sawshave poor arrangements for tightening and maintaining the tightenedcondition of the blade in the chuck.

Additionally, many chucks presently used on portable reciprocating powersaws are poorly arranged for removal of the shank of a blade remainingin the chuck when the blade breaks off at the front of the chuck.

SUMMARY OF THE INVENTION The chuck of the present invention is a simple,convenient arrangement which is relatively short in length, which iseasily applied to the reciprocating shaft of known portable saws, whichprovides for easy removal of the broken shank of a blade in the chuck,and which readily accepts and firmly holds blades of different widths.

The foregoing advantages of the present invention, while of substantialimportance to even an occasional user of such portable reciprocatingpower saws, are of extreme importance to the craftsman who daily uses apower saw in his work. Such power saws are rugged tools while the bladesare of necessity relatively fragile. Use of such saws by builders,carpenters, plumbers and sheet metal craftsmen requires that the saws beconstantly interchangeably used for cutting many different materialssuch as wood joists, floors and walls, plaster, metals and plastics.Such heavy and varied uses require that the blades be changed to providedifferent tooth configurations and sizes for different cuttingfunctions, and to replace dull or broken blades. In reductions topractice of the present invention it has been found that blades withspecial shanks are not required. Any available stock blades of differentshanks and widths are easily inserted and locked into the chuck, firmlyheld therein under heavy sawing conditions, and easily replaced evenwhen broken at the front of the chuck.

The primary object of the present invention is to provide a simple,compact, relatively short, chuck for known portable reciprocating powersaws which will accept a wide range of commonly available blades, whichwill firmly hold the blades for cutting, and from which blades or bladeparts may be easily removed.

The primary object of the present invention is achieved by a basic chuckconstruction in which, among other elements, the saw shaft slot and theblade slot are overlapped and in which the rear portion of the bladeslot is open.

Other objects and features of the invention will be apparent upon aperusal of the hereinafter following specification and the drawing.

DETAILED DESCRIPTION OF THE DRAWING FIG. 1 is an elevational view of achuck constructed according to the invention with fragmentary portionsof a blade and a portable reciprocating power saw;

FIG. 2 is an elevational view of the structure of FIG. I viewed from theopposite side;

FIG. 3 is an elevational view according to FIG. 1 with the blade and sawremoved;

FIG. 4 is a top plan view of the structure shown in FIG. 3; and I FIG. 5is an end view of the structure of FIGS. 3 and 4 taken from the front ofthe chuck.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A fragmentary view of aknown portable reciprocating power saw is shown at 10 in FIGS. 1 and 2.The saw 10 reciprocate an extending shaft 11 which is caused to axiallyreciporate when the saw is operated.

The preferred embodiment of the invention which is shown at 12 comprisesa one-piece chuck assembly. The chuck I2 is generally rectangularlyshaped and secured to the shaft ll of the saw 10 by a fastener 13. Toreceive the end of the shaft 11, one side of the chuck 12 is providedwith a shallow slot 14. The outer end of the slot 14 is open and theinner end terminates in a semicircular wall portion. The slot 14 has awidth substantially equal to the width or diameter of the end of theshaft 11 of the saw 10. The longitudinal axis of the slot 14 is disposedat an angle to the longitudinal axis of the chuck 12 so that the chuck12 is angled slightly downwardly when applied to the shaft 11 of the saw10. The rear end wall of the chuck 12 is perpendicular to thelongitudinal axis of the slot 14.

Preferred forms of the saw 10 are provided with circular shafts 1 l theouter end portion of which is formed with a flat portion indicated at 15in FIG. 2. The flat portion of the shaft 11 is received within the slotM as shown in FIG. 1. The flat portion of one known saw is formed in twosteps or levels, one of which will be re ceived within the deeper slotportion 116 shown in FIGS. 3 and 4.

The chuck 12 is further provided with a hole 17 extending therethroughand into the slot 14 to receive the fastener 13. One known saw 10 isprovided with a threaded hole which with which the hole 17 may beaxially aligned to receive the fastener 13 to secure the chuck 12 to theshaft 11. If the hole in the shaft 11 is not threaded, the hole 17 maybe threaded and the fastener 13 is then inserted from the opposite sideto secure the chuck 12 to the shaft 11.

The side of the chuck l2 opposite from the side having the slot 14 isprovided with a slot 18 which extends parallel to the longitudinal axisof the chuck 12. The forward side portion of the slot 18 is transverselycovered by a blade securing cover portion 19. The portion 19 is formedas an integral part of the chuck l2, and the slot 18 has a depthsufficient to receive the thickest blade intended to be used with thechuck 12. The longitudinal inner end of the slot 118 terminates adjacentto the hole 17. This arrangement provides for a substantial longitudinaloverlap of the slots 14 and 18. The invention contemplates that thelength of the chuck 12 may be reduced from that shown in the drawing bya further longitudinal overlap of the slots 14 and 18 with the slot 18terminating immediately adjacent to the hole 17.

The forward end of the slot 18 opens into the forward end wall of thechuck 12. The forward end wall of the chuck 12 is perpendicular to thelongitudinal axis of the slot 18.

The rearward end of the slot 18 terminates in an end wall which isformed as two adjacent semicircles defining a projection 20 which isdirected longitudinally forwardly of the chuck 12 along the longitudinalaxis of the slot 18. The inner end wall of the slot 18 will cooperatewith blades of various widths from a blade as wide as the slot 18 toblades of less than one half the width of the slot 18 to engage theinner end of the blade and hold the blade against pivoting in the planeof the blade.

A blade, such as blade 21, is secured in the slot 18 by a fastener 22.The fastener 22 is threaded through an appropriate hole in the portion19 as shown in the drawing. The inner end of the fastener 22 is urgedagainst one side of the blade 21 to firmly lock the blade 21 within theslot 18.

The open rearward portion of the slot 18 enables a user to visuallyobserve that the blade 21 is completely seated against the inner endwall of the slot 18, and further provides an easy arrangement forremoving the remaining or shank portion of a blade which in use maybreak flush with the forward end of the chuck 12. Once the fastener 22is loosened an instrument such as a screwdriver may be used to urge theremaining portion of a broken blade forwardly out of the slot 18sufficiently to enable one to grasp the forward end of the remainingportion and draw it from the chuck 12.

Having described the invention, it is to be understood that thepreferred embodiment may be changed by one skilled in the art within thespirit and scope of the hereinafter following claims.

We claim:

1. A chuck for a portable reciprocating power saw comprising, asubstantially rectangular member, a first slot in one side of saidmember, said first slot opening into one end of said member and adaptedto receive the operating shaft of a portable reciprocating power sawtherein, first fastening means for securing said shaft in said firstslot, a second slot formed in said member in the side thereof oppositefrom said one side, said second slot opening into the other end of saidmember opposite from said one end, said member having an integral coverportion extending transversely over a longitudinal portion of saidsecond slot, said cover portion extending from said other end of saidmember to a position intermediate the ends of said second slot, theportion of said second slot longitudinally between said cover portionand the inner end of said second slot being open, the inner end portionsof said first and second slots longitudinally overlapping, said secondslot adapted to receive one end of a saw blade therein with said bladeextending from said other end of said member, and second fastening meansin said member for securing said blade in said member.

2. In a chuck as defined in claim 1, wherein the longitudinal axis ofsaid first slot is disposed at an angle to the longitudinal axis of saidmember, and said one end of said member lies in a plane perpendicular tothe longitudinal axis of said first slot.

3. In a chuck as defined in claim 1, said first fastening meanscomprising a fastener extending through said member and said shaftperpendicular to the longitudinal axis of said shaft.

4. In a chuck as defined in claim 1, the inner end of said second slotbeing configured as two contiguous semicircles with the juncture of saidsemi-circles forming a projection extending along the longitudinal axisof said second slot and toward said other end of said memher.

5. In a chuck as defined in claim 1, said second fastening meanscomprising a fastener threaded through said cover portion in a directionperpendicular to the plane of said second slot and any blade carriedtherein to engage one side of said blade in an urging relationship ofsaid blade against the bottom wall of said second slot.

1. A chuck for a portable reciprocating power saw comprising, asubstantially rectangular member, a first slot in one side of saidmember, said first slot opening into one end of said member and adaptedto receive the operating shaft of a portable reciprocating power sawtherein, first fastening means for securing said shaft in said firstslot, a second slot formed in said member in the side thereof oppositefrom said one side, said second slot opening into the other end of saidmember opposite from said one end, said member having an integral coverportion extending transversely over a longitudinal portion of saidsecond slot, said cover portion extending from said other end of saidmember to a position intermediate the ends of said second slot, theportion of said second slot longitudinally between said cover portionand the inner end of said second slot being open, the inner end portionsof said first and second slots longitudinally overlapping, said secondslot adapted to receive one end of a saw blade therein with said bladeextending from said other end of said member, and second fastening meansin said member for securing said blade in said member.
 2. In a chuck asdefined in claim 1, wherein the longitudinal axis of said first slot isdisposed at an angle to the longitudinal axis of said member, and saidone end of said member lies in a plane perpendicular to the longitudinalaxis of said first slot.
 3. In a chuck as defined in claim 1, said firstfastening means comprising a fastener extending through said member andsaid shaft perpendicular to the longitudinal axis of said shaft.
 4. In achuck as defined in claim 1, the inner end of said second slot beingconfigured as two contiguous semicircles with the juncture of saidsemi-circles forming a projection extending along the longitudinal axisof said second slot and toward said other end of said member.
 5. In achuck as defined in claim 1, said second fastening means comprising afastener threaded through said cover portion in a directionperpendicular to the plane of said second slot and any blade carriedtherein to engage one side of said blade in an urging relationship ofsaid blade against the bottom wall of said second slot.